Power-transmission toothed gearing



B. R. WINGFIELD. POWER TRANSMISSION TOOTHED GEARING.

APPLLCATION FlLED AUGSG, 1918.

Patented Aug. 31, 1920.

2 SHEETS-SHEET l B. R. WINGFIELD. v POWER TRANSMISSION TOQTHED BEARING.

APPLICATION FILED AUG.6.1918.

l 35 l 5-97 0 Patented Aug. 31, 1920.

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BERNARD R. WING-FIELD, OF WESTDRAYTON, ENGLAND.

POWERTRANSMISSION TOOTHED GEABING.

Specification of Letters Patent.

Patented Aug. 31, 1920.

Application filed August 6, .1918. Serial No. 248,639.

Mv invention which is applicable to power installations generally but more particularly to those. driving ships propellers, .relates to a reducing gear for driving a shaft in either direction in which the driving shaft rotates continuously in the same direction and drives the driven shaft in one direction through a toothed wheel having external teeth and in the other direction through a toothed wheel having internal teeth. These driven wheels are mounted free to rotate on the driven shaft and are coupled thereto suitably with the direction of rotation required.

The invention consists in an improved ar rangement and combination of parts as hereinafter described and claimed.

Figure 1 is a part plan of the gear.

Fig. 2 is a plan to an enlarged scale of an arrangement of valves for controlling introduction of pressure fluid through the shaft for operating the clutches.

In this case the wheels on the driven shaft are free to rotate on the shaft and are adapted to be coupled thereto by hydraulically operated clutches; they are driven by corresponding pinions fast on the driving shaft which is duplicated in well-known manner.

a is the driven shaft of a turbine double reduction gear for ship propulsion. It is flanged at I) for connection with the propeller shaft. a suitable thrust bearing being interposed between this flange and the :propeller. is the final gear wheel for the ahead direction of rotation and has external teeth while (Z the final gear wheel for the astern direction of rotation, has internal teeth. Both wheels are free to turn onshaft a but cannot slide thereon. The wheel c is in two parts, and the parts are engaged respectively by pinions e on shaft 9 which also carries pinion f driving the wheel d. Pinions e and f are mounted fast on, or forged in one with, the-shaft g. Each shaft 5 is driven through a wheel h mounted between the two parts of wheel 0, by a separate turbine. This double reduction by means of wheels it would not be necessary if low speed motors were used instead of turbines in which case these wheels would be omitted and shafts g driven directly by the motors.

Two hydraulically operated clutches z, i

are provided for coupling the wheel a to its shaft, one at each end of the nave of the two-part wheel, so that by their opposed pressure axial thrust from the clutch members is avoided. The pressure fluid introduced through passage is in the shaft passes through passages Z, Z into the extensible fluid pressure chambers, m, m where it .forces friction clutch disks a, n. against friction surfaces 0,0 on the wheel 0. The bosses j, j of the friction clutches are keyed to shaft a, while the bosses p, p to which disks n, n are bolted respectively are mounted on keys on bosses g, j so that the disks can slide axially. similarly operated clutch, as will presently be described, serves to couple wheel 03 to the Shaft.

Whenever wheel 0 is. clutched to the shaft, wheel at is running free thereon and vice versa. ment whereby the two wheels cannot be coupled to the shaft by their respective clutches at the same time and. for using the pressure fluid for lubricating the freely running wheel. A further arrangement permits use of the pressure fluid for lubricating both wheels, when both are freely running.

These arrangements are illustrated in Fig. 2. r is a cylindrical body bolted to the end of shaft a so that passages la and a which it contains register with passages la and a respectively in the shaft. Flanged sleeves s and t formrunning joints with body 1' and serve for introduction of pressure fluid into passages is, a respectively through pipes s, t, controlled by valve 11. The latter comprises two pistons 10, w mounted on a rod connected with a lever m. In the position of this lever shown in the drawing, both pistons are in their middle'position in which ipes s, t, and therefore'passages 70', u and a, are both open to the exhaust 2. When the lever is moved into position w, the pistons are in their extreme left hand position, wherein w still leaves ipe 25 open to exhaust, but piston w (the new position of which is shown in dotted lines) has cut off pipe 8' from the exhaust and has opened into the pressure fluid inlet port 1 When the lever is moved into position m the pis- The invention includes an arrange-- tons are in their extreme right hand position v and w has opened pipe 8 to the exhaust while w has cut off pipe 23' from the exhaust and opened it to inlet port 3 It is to be noted that the pistons w andw are so arranged that the former cuts of! pipe 8 from the inlet port y and opens it to the exhaust .2 before piston w opens pi e t to the inlet port I and vice versa: t us it is impossible for pressure to be maintained in both pipes at the same time.

Referring to Fig. 1, passage u in shaft a is connected through passage u with the pressure chamber m of the clutch 2' which is slidably mounted on a key on shaft (1. When the pressure fluid passes into this chamber it forces plate n against plate 03' which is bolted to the nave of wheel 03 and then the pressure fluid acting on the opposite end of the chamber moves the clutch i to the right hand (in Fig. l) bringing the friction clutch disk or plate n agalnst the other or left face of plate d, thus coupling the wheel to the shaft, but with balanced axial.

pressure.

As already stated a like efl'ect follows passage of pressure fluid from passage is into clutches m, m. It will be noted that passage u is connected by passage with the surface of contact of wheel 0 with shaft a fluid pressure, it will be seen that the position w of lever 00 is that for steaming ahead, namely with pressurefluid operating clutches m, m and lubricating Wheel d, while the position .11 is that for going astern, namely with pressure fluid operating clutch i and lubricating wheel 0.

In the middle position of a? all clutches are open to the exhaust and both wheels are running free, so that although pressure fluid is not in use for operating a clutch it is still required for lubricating the wheels.

For this purpose the exhaust pressure in 2 is maintained high enough to insure lubrication, but below that necessary for operating a clutch. The exhaust contains a relief valve 1) which allows the fluid leaving a clutch to flow until the pressure is below a certain predetermined value, whereupon this valve closes and the remaining oil in the clutch flows through passages q and 9 As soon as the pressure is slightly further reduced by escape from the lubricated surfaces, a check valve 0 is opened by an auxiliary supply of fluid, under an intermediate pressure, flowing through pipe 14" and exhausting through pipe u.

The particular construction shown is only.

an example of the invention. It will be apparent that the wheel with external teeth,

prising a wheel having external teeth and a wheel having internal teeth both mounted on the shaft to be driven, pinions on the driving shaft gearing with the said toothed wheels, the gears on one of the shafts being fast on that shaft while the co-acting gears on the other shaft are mounted freely thereon, hydraulically operated clutches adapted to con le the free gear wheels alternatively to their shaft, and valve gear controlling the operation of the clutches and the supply of a lubricating fluid film to the gear wheels, substantially as described.

2. A reducing gear for driving a shaft in either direction of rotation from a shaft rotating uni-directionally, comprising an externally toothed gear wheel and an internally toothed gear wheel both loosely mounted on the shaft to be driven, pinions fast on the driving shaft meshing with the said gear wheels, hydraulically actuated clutch devices for the two gear wheels rotatably secured to the driven shaft but having axial freedom thereon, a system of ducts connecting the clutch devices, with a source of pressure fluid, and valve gear controlling the supply of pressure fluid and operating to actuate the clutch devices alternatively and simultaneously sup ly a lubricating film of pressure fluid to t e unclutched gear wheel, substantially as described.

In testimony whereof I have signed my name to this specification.

BERNARD R. VVINGFIELD. \Vitnesses E. CHARLES WAY, S. CowLEs. 

